Heat damper?

RL Chilton

Anyone know if I can remove the heat damper from an exhaust manifold without destroying the damper? Procedure?

Be nice to save, if possible.

[Deleted User]

The butterfly plate is welded to the shaft. You have to use a bare hacksaw blade to cut the shaft at both ends of the butterfly inside the opening. (Sometimes if you're lucky you can use a dremel tool to grind the welds holding the butterfly to the shaft so you can remove the butterfly plate without cutting the shaft. Then if any weld remains on the shaft grind it down so you can slide the shaft out of the manifold). Make a note of the butterfy position on the shaft at full open and full close position, because you'll have to tack weld the butterfly to the new shaft in the correct position. Salvage the butterfly plate by grinding the welds holding it to the shaft. Salvage the counterweight by driving out the pin holding it to the cut piece of the shaft it is attached to.



Pretty hard to do this on the car, much easier if you remove the manifold. You'll probably have to fabricate a new shaft. The above procedure is paraphrased from the manual.



Tom



P.S.: Above procedure is for stepdown 6cyl exhaust manifolds. 8cyl stepdown exhaust manifolds use a tapered shaft that can be driven out without cutting the shaft.

[Deleted User]

Don't know if they remained anywhere near the same through the years, but I removed the stuck one on my '36. It had a stem that goes through the manifold. I just squirted it good with penetrating oil then began to loosen it using vicegrips on the stem until it was turning a little. Removed the two bolts on the front side and GENTLY tapped the back side out with a brass hammer.

I had the exhaust mani out at the time so I had to replace the gasket, but after seeing how it worked, I could have done this without removing the exhaust manifold.

Good luck...slim

RL Chilton

Ken U-Tx wrote:

Russell, are you refering to the manifold on "Doc". The butterfly is already cut out of that manifold, just the ends of the shaft were still in place. They cut it out with a torch. I thought I showed it to you when we had it off off the block. Or are you talking about one of the other exhaust manifolds you have?

No, not Doc, I know all about that one. It's the NOS manifold I have for the convertible. It's time to get it powder-coated. Just about have everything I need now for the top part of the motor and wanted to get it ready to go. Just hoping I could remove the damper without permanently damaging it so it could be put back one day, if wanted.

[Deleted User]

Russell:

One of our exhaust manifolds has a split shaft heat riser shaft. Appears to be brass, but may not be. If yours is split, removing the weld as previously discussed, should allow you to drive the shaft to one side(after removing the fore mentioned pins). Good luck, havent removed one my self yet but took the manifold off, seperated the halves, sand blasted them and freed the damper. My next step is to do what you are planning. Let us know your techique.

The dual outlet exhaust manifold adapter should work well without the damper. Hudsonly, Bob

RL Chilton

bobdriveshudson wrote:

Russell:
One of our exhaust manifolds has a split shaft heat riser shaft. Appears to be brass, but may not be. If yours is split, removing the weld as previously discussed, should allow you to drive the shaft to one side(after removing the fore mentioned pins). Good luck, havent removed one my self yet but took the manifold off, seperated the halves, sand blasted them and freed the damper. My next step is to do what you are planning. Let us know your techique.
The dual outlet exhaust manifold adapter should work well without the damper. Hudsonly, Bob

Hi Bob! I'll keep you posted. I would've bought one of your split manifolds, but I have one of the previous re-pops, as yet un-used, which I plan on using. Did you make a plate that bolts to the bottom with pipes attached, which start the exhaust on it's way out of the manifold? Still have to fabricate or buy one.

hudsonguy

Brings to mind the advice Walt M. gave me the very first time I met him ('03 Nationals). He said to take that heat riser out and to 'throw it as far as you can'!



So maybe it's not too valuable in the grand scheme of things.

RL Chilton

hudsonguy wrote:

Brings to mind the advice Walt M. gave me the very first time I met him ('03 Nationals). He said to take that heat riser out and to 'throw it as far as you can'!

So maybe it's not too valuable in the grand scheme of things.

I, of course, agree wholeheartedly. Particularly here in the south, the damper is simply not needed and restricts too much flow, generating more heat than necessary. A lot of exhaust manifolds end up cracking around #3 & 4 area of the exh. manifold. Up north, the damper would still do it's job, same as when the Hudson engineers designed it. But, these days, realistically, the majority of Hudson owners do not drive their cars in colder weather, where the damper would function at it's peak potential.

My thoughts were to simply to save it for historical and/or posterity sake, so that if someone, someday, wished to "put it back stock", this particular facet would be easily remedied.